Production of a soap product



Patented Feb. 14, 1933 UNITED ,STATES PATENT OFFICDE DALLAS R. LAMONT,OF BROOKLNN, NEW YORK, ASSIGNOR TO COLGATE-IALMOLIV'E- PEET COMPANY, OFCHICAGO, ILLINOIS, A CORPORATION OF DELAWARE, AND THE PROCTER & GAMBLECOMPANY, OF CINCINNATI, OHIO, A CORPORATION OF OHIO PRODUCTION OF A SOAPPRODUCT No Drawing.

The present invention relates to the production of a soap product inreasonably finely divided state such that the component particles of theproduct are used in mass rather than as separate entities, and it has todo particularly with a novel process for the production of soap productsof this general class which products, upon introduction into water as incommon washing practice, exhibit the property of becoming thoroughlywetted practically immediately throughout their entire mass and of goinginto solution or admixture in water with particular readiness and speedand with a positive resistance to formation of slowly ordifficultysoluble lumps or agglomerates. The invention .alsocontemplates an improved soapproduct which possesses the properties juststated, the individual particles of which have certain novel and usefulstructural characteristics and physical properties not heretoforeattained in products of this class; It is an object of the inventiontoprovide process and product of the character just indicated. The presentinvention is, in'a sense, related to the invention of my prior PatentNo. 1,652,900.

It is an object of the invention to provide a soap product consisting ofindividually distinct separate independent particles formed as such byspraying or atomizing the soap into a spray of definitely segregatedparticles and maintaining this condition of separate identity of theparticles by preventing such subsequent contact between the particles aswould cause them to adhere, agglomerate, run together, or otherwisebecome physically connected so as to necessitate grinding, breaking up,crumbling or'disintegrating to reduce the product to the ultimateparticle condition and size attained in the finished product, and whichrespective separately formed particles exhibit a microscopic cellular,porous or spongeous structure within each typical average particleextending substantially throughout the bodof the particle withoutnecessarily embo ying a characterizing principal interiorvoid andwithout exposin an unprotected fragile structure at the sur ace of theparticle. The production Application filed April 23,

has been proposed heretofore.

1931. Serial No. 532,278.

has ever attained commercial success. Soap products so produced are notacceptable commercially because of such factors, among others, asnon-uniform or inadequate development of the porous structure in someportions of the soap material, formation of excessively large pores orcells which act as insulation against thorough wetting and rapiddissolving, structural instability due to exposed fragile cellstructure', dusting and setthng in the package, ragged and non-uniformappearance, formation of a tough slow dissolving skin upon portions ofthe soap which are exposed to heat during processing, relatively slowspeed of dissolving, and substantial residue of insoluble or verydiflicultly soluble material. The present invention provides athoroughly acceptable commercial soap product free from all of the abovenoted objections and disadvantages which are inherent in soap productsmade by pufiing in mass and subsequently disintegrating,

It is an object of the invention to provide for inducing and maintainingwithin the respectfve individual particles of the soap prodnot of thisinvention a characterizing cellular or porous structure of the kind justreferred to, the cells or pores being of microscopic size sufficientlysmall to promote quick access of water to every part of the soapmaterial by capillary action and being enclosed by a protective butwater permeable outer surface so that both physical stability and rapidand complete dissolving are obtained.

It is an object of the invention to provide the aforesaidcharacteristics in a product of the class described and, as a' matter ofcombination, to provide said characteristics ina soap product whoseparticle size is sufiicient ly small so that the advantages possible byreason of said characteristics can be fully realized. To explainfurther, a product having particles averaging say one fourth inch indiameter orthickness are so large that they dissolve but slowly even ifthey have a pore structure of proper size and distributlon, and furtherit is practically. imposslble to make particles of this size without atoughened difficulty soluble relatively impervious outer skin andwithout excessively large cells. I have found that the upper particlesize limit for really good wetting and dissolving properties is abouttwo millimeters as determined by no substantial proportion of theparticles of the product being retained on a standard ten mesh sieve. Itmay be noted in passing that very large amounts of fine floury dust-like-material may also impair the dissolving properties of the product.

It is also an object to provide a novel process for establishing andmaintaining the aforesaid protected microscopic cell structure in thematerial of the individual component particles of a spray-solidifiedsoap product, the particles of the product being characterized either bypresence or absence of principal voids, as desired, and the product as awhole being'characterized by notable ease and rapidity of wetting anddissolving. It has been proposed to produce a spray dried soap productthe particles of which have an internal cellular structure produced bythe expansion of steam within the soap particle and not necessarilycharacterized by the presence of a principal void. No claim is madeherein to such a process or to the product resulting therefrom, suchprocess and product having been disclosed and claimed in my abovementioned Patent No. 1,652,900. \Vhen, pursuant to the process of thatpatent, the temperature is lowered sufiiciently and other processconditions are adjusted to roduce a relatively slightly 'pufi'ed pro uctFigure 3 of patent), the roduct becomes, as

escribed in said patent, ess rapidly soluble and of heavier bulkingweight. The present invention provides a process for producing particlesw ich can be made cellular throu hout without substantially impairingthe ssolving properties of the product. The present process alsoprovides a means for producing the said cellular structure moreuniformly throughout the. respective particles of the'product than ispossible by the process of the aforesaid patent when the process is soconducted that only slight pulling is produced. The process of thisinvention is, 1n a sense, an alternative and a further development uponthe process of said patent.

It is a further object to provide a process of. the character referredto which is feasible from a commercial standpoint as a continuousthoroughly practicable process capable of producing the product in largetonnage at reasonable cost.

The invention probably can best be described by first giving anillustration of one embodiment of the process. The following example isgiven as one detailed process tice and while it is maintained at atemperature of between 180 F. and 210 F. is pumped under a pressure ofbetween 100 lbs. per square inch and 250 lbs. per square inch through aline or pipe. A gas such as nitrogen, carbon dioxide, air or the like,is embodied in the flowing stream of soap by being introduced intocontact with the soap in an amount in excess of that which the soap willretain at atmospheric pressure. The commingled flowing soap and gas aremaintained in the restricted pipe under the pressure, for approximatelythree minutes to insure a reasonably thorough distribution of the addedgas throughout the entire mass of soap. A substantial amount of the gasbecomes dissolved in the soap and any excess of gas becomes admixed withthe soap mass in uniformly distributed finely divided condition. Thesoap with its'contained gas is then discharged through a suitable exitmeans or nozzle at the pressure of between 100 lbs. per square inch and250 lbs. per square inch which atomizes or sprays the soap in suchmanner as to subdivide it into great numbers of small independentdefinitely segregated particles. complement of contained gas is sprayed,as just described, into a region of pressure substantially lower thanthat obtaining in the pipe line, thereby effecting release of thecontained gas which the soap is incapable of holding at the reducedpressure. Also, the region into which the soap with its content of gasis sprayed is purposely conditioned to effect rapid conversion of thematerial of the small sprayed particles into form retaining conditionas, for example, by rapidly extracting the moisture from the respectivesprayed particles at a relatively low temperature level of between 200F. and 300 F. which, due to the small size of the sprayed particles, thesegregated condition of the particles, and other factors, can beaccomplished readily in the brief space of three or four seconds bycirculating warm air intimately about the respective particles as theyare formed at the spray. The result is a substantially uniform releaseof gas throughout the entire body of each respective small articleeffecting the formation of a'myriad of minute cells distributedthroughout the body of each partido and maintained of microscopicdimensions by reason of the rapid conversion of the material of theparticle into form-retaining condition which takes place substantiallysimultaneously with the gas release, thus preventingescape of the gasfrom the particles'and preventing uniting of the small gas pockets toform excessively large cells.

, fine powders. The particles of the product are ordinarily potatoshaped individually distinct units .of reasonably uniform size range andgenerally rounded outline free from sharp angular corners, and the like,the

particles being capable of ready independent relative movement withoutclinging together. It is immediately distinguishable from a flaked,comminuted, broken up or disintegrated product. VVhen the product isplaced in water and stirred the entire mass of the product becomesthoroughly wet practically immediately, and the product dissolves withparticular readiness and speed and with a positiveresistance to theformation of difficultly soluble lumps or agglomeratcs.

The advantages of the present product as a commercial article are due toseveral controlling physical charca'teristics, no one of which alone issufiicient but which, in combination, give rise to the present product.

' Among these several physical requisites are average particle mass andcertain limits of maximum and minimum particle mass and size. Theparticles of the preferred product are of small individual mass butnevertheless contain sufiicient amounts of soap so that they are capableof ready independent relative movement and are readily separable uponagitation of the product as by pouring into water. The minimumpermissible particle mass is that which is just large enough to insurefreedom from tendency of the par-' ticles to cling together and to formsmall lumps or spots in water which do not quickly dissolve.Irrespective of the average par- I ticle mass, it is also desirable thatthe product should notcontain an excessive amount'of fine dust or alarge proportion of unduly large particles. The particles of the generalrun of the preferred product are sufficiently small so that, whenintroduced into water, the water can practically immediately prmecd bycapillary action to the inner portions of the particles, thus quicklypermeating the entire body of the particle and dissolving the product ina few seconds. It will be understood that there is a considerable rangeavailable-between the preferred maximum and minimum limits abovespecified. In a product made according to the process outlined above, asatisfactory general run of particle size is between 80 mesh and 20 meshas determined by the major portion of the product being retained on astandard 80 mesh sieve and passing a standard 20 mesh sieve. It ispreferable that the product should not contain large amounts of materialwhich pass a 100 mesh sieve and should not contain substantial amountsof product which are retained on a 10 mesh sieve. The abovespecifications as to particle size and mass are givenlargelyby Way ofexample as a guide to the production of a preferred product, and theywill vary to a certain extent depending upon the characteristic internalstructure of the particle and other factors, it'being understood thatthe satisfactory action of the product in water is the ultimateessential to which the product must conform.

In combination with the requirements of particle mass and size givenabove, it isimportant that the component particles of the product beseparate individually formed units as distinguished from particles,fragments or portions derived by comminuting or breaking up a largermass of soap which itself is in solidified or self-sustaining condition.The particles of the present product are characterized by relativelysmooth exterior surfaces free from exposed fragile cell structure.

In combination with the various structural particle characteristicsdescribedabove, the product of the present invention may be made toconsist of particles which, as a matter of general run, comprise acapillary or cell structure which extends throughout the particle andwhich consists of great numbers of tiny cells distributed throughout thebody of each small particle. This interior capillary or cell structureterminates exteriorly in a substantially continuous surface or outer portion which covers and protects the fragile interior cell structure butthrough which, under the microscope, the above described cellstructureis visible. This protective outer portion is extremelypermeable to water and is not in any sense a tough diflicultly solubleskin such as is produced on soaps pufi'ed in the form of a cake or film.\Vhen any particle or group of particles is brought into proximity withwater, the water is absorbed .the presence of great numbers of cellsextending throughout the entire body of each small sprayed particleprovide a structure of optimum characteristics for water absorp tion, aresult not heretofore obtained uniformly throughout a product composedof pargicles not characterized by a principal v01 Referring back to theoutline of the process given above, the relation of the respective stepsof the process to the characteristics of the ultimate product can now bebetter described, as can also certain variations and modifications ofthe process and the resulting product. The present invention relates tosoap, and the kinds of soap primarily conplated by the invention arepure soa'p as ordinarily produced by the usual methods of commercialmanufacture, such soaps in admixture with various amounts of certainappropriate alkaline materials as, for example, common laundry soaps,soap powders which usually consist of soap and relatively largeproportions of sodium carbonate, and in general any material which is asoap product primaril adapted for cleansing purposes and whic comprisesa proportion of soap sufliciently large to enable it, under theconditions of the process, to attain and maintain the physical structureabove described. Soap, as it occurs in the boiling pans in the regularcourse of manufacture, normally contains about 70% of solids. When suchsoap is admixed with various alkaline materials, according to commonmanufacturing practice, this concentration of solids is ordinarilysomewhat diminished, for example, to the general neighborhood of Suchsoaps as just referred to are, as they normally occur in the regularcourse of manufacture, hot or warm heavy flowing liquids partaking of asomewhat plastic-character, short as distinguished from viscid, butnevertheless capable of flowing readily through pumps and pipe lines,seeking'a substantially level surface in a container, and

spraying readily through an appropriate atomizer. It is such relativelyhigh solid content soap which is preferable for use in the presentprocess. In carrying out the process with ordinary filled laundrysoaps,a solid content of approximately 60% is satisfactory. The soap, asdelivered to the present process, is maintained sufliciently hot so thatit will flow readily through pipelines and will break up into asatisfactory spray. A soap temperature of from say 180 F. to 210 F. is agood average working temperature, although it will be understood thatthe lower temperature limit at which the soap will spray'satisfactorilyvaries with soaps of different composition and water content and canreadily be determinedby experiment with any particular soap. The figuresgiven above do not represent limits; they merely specify a range withinwhich satisfactory results can be obtained. Some soaps of regularcommercial manufacture can be sprayed satisfactorily at temperatures ofas low as 150? or 160 F. Also, soap temperatures substantially higherthan the 210 F. figure given above can be employed satisfactorily, andsubstantial increase of the soap temperature has a certain effect on theproduct which will be described below. i

The soap is then placed under pressure, and incorporation of gas thereinis effected. The pressure may vary over wide limits depending upon theresults desired. The ressure has a bearing on the character 0 the spraywhere a pressure spray is'used and therefore must be sufliciently highto produce a satisfactory spray of well separated parti= cles ofappropriate size and uniformity of size. Very high pressures at thespray nozzle give rise to particles of excessively small size produceobjectionable wear on pumps and nozzles and increase the power cost ofthe operation. Very low pressures ordinarily give rise to a ragged sprayresulting in a wide range of particle size and production of excessivelylarge particles or fragments at the spray which cannot be thoroughlytreated to form a satisfactory product and'which often fall upon andstick to the parts of the apparatus. The amount of gas released fromsolution within the respective sprayed particles depends somewhat uponthe pressure difference which the soap experiences, and thereby has adefinite effect on product characteristics as described more fullybelow. The vigor with which the contained gas is releasedand the kind ofcell structure produced by it within the individualsoap particles isdependent upon the pressure drop to which the soap is subjected. Thepressure employed should be sufficiently high so that the respectiveparticles of the finished product exhibit a well defined microscopiccell structure and possess the above described desired properties ofrapid wetting and dissolving in water. Ordinarily, relatively lowpressures produce entirely satisfactory particle characteristics and areperhaps preferable from an operating standpoint. Pressures of from 100to 250 pounds per square inch employed in conjunction with a pressurespray having an orifice of from lto 2 mm. in diameter will, whenemployed in combination with the rocess conditions set forth above, givesatis actory, results. This data is, of course, given merely as anillustration of specific conditions under which satisfactory results canbe obtained.

The gas is preferably introduced, as described, into a flowing stream ofthe soap,

and the admixed soap and gas are carried along through a length ofpipe'under desired pressure for a period of time suflicient to insurereasonably complete distr'bution of the gas throughout the body of soapand dissolving of a substantial amount of the gas in the soap.Satisfactory results have been obtained by drawing in gas at the suctionside of the soap pump, but it is to be understood that :the soap may becharged with gas in any desired manner either with or without the use ofan air compressor, gas stored in presure cylinders, or mixing apparatus.By way of example, it may be stated that passage of the admixed soap andair through a three-quarter inch line under pressure for about threeminutes has given satisfactory results. The determining factor is properdissolving and distribution of the gas in the soap as evidencedby thepresence of the desired type of cellular structure in the typicalparticles of the finished product. If the gas is not uniformlyincorporated throughout the soap, the desired structure will be presentin some of the particles and will be absent or insufii-.

particles. The spray of soap particles is di-v rected into an openchamber or space sufficiently large so that the spray may spread out toits full extent without impinging upon parts of the apparatus or otherobstructions and so'that the particles formed float freely away from thespray and remain dispersed in the atmosphere of treating gas w?thin thespray chamber without coming into contact with the walls, bottom or any,other apparatus parts until treatment of the particlcs is completed.Separate formation and segregation of the particles of the product arethus effected, and the particles maintain their separate nature in thefinished product.

The chamber into which the gas containing soap is sprayed is maintainedat a pressure substantially lower than the pressure on the 3 soap priorto spraying. The excessof gas which the soap is incapable of retainingat this reduced pressure thereupon releases itself within the respectiveind vidual'particles. The subdivision of the soap into individualparticles occurs substantially immediately at the spray, and the releaseof gas from solution probably takes place largely within the respect veindividual particles after they-have been formed and segregated,asevidenced by the cellular structure of microscopic dimensions formedwithin the body of the particle enclosed by a relatively smooth finishedexterior. The release of gas occurs very uniformly throughout the bodyof the particles, and the result is the formation of a myriad ofmicroscop'c gas cells distributed throughout the body of each smallparticle of the product. f

An atmosphere or current of warm gas,

such as air, which promotes rapid drying of the sprayed particles intoform-retaining condition is maintained in the spray chamber. The smallsprayed particles are entirely enveloped in this gas,and in a manner ofa very short time the particles are reduced to form-retaining conditionthroughout their entire body. This quick drying and conversion of theentire substance of the respective individual particles takes placesubstantially concurrently w th the release of gas within the respectiveparticles and the formation of such released gas into minute cells, andhence has the effect of solidifying, the particles into permanent formand maintaining the cells formed by the gas release of microscopicdimensions, not allowing them to escape or combine and thus formrelatively large voids within the particles. The surfaces of theparticles entirely enclose and protect the fragile cellular internalstructure; no fragile cell structure projects itself to the exterior ofthe particle. With other condit ons of the process as set forth above,drying air of say 200 F. and upward can be employed successfully in theproduction of the product as described.

From the above description it will be Ob-f.

served that the process of the present invention comprises a relativelylarge number of variables which may be made use of in controlling andvarying the characteristics of the productwithin certain limits. Theprinciple variables, assuming that the process is being applied to agiven kind of soap product of the class defined above, are proportion ofsolids in the soap, temperature of the soap, pressure applied to thesoap relative to the pressure into which the soap is sprayed, amount ofgas incorporated in the soap, size of particles produced at'the spray,and effective temperature level of the atmosphere in the spray chamberduring the conversion of the soap particles into form-retainingcondition. In the description of the process given above, a value foreach of these variables has beenstated by way of illustration. Theinvention is not, however, confined to this particular form of productand is not confined to the limitsof the several variables specificallyset forth above. The considerations given immediately below with respectto the several principal variables will aid in defining the scope of theinvention and in pointing out its possible variations and adaptations.

Soap containing a lesser content of solids than that given by way ofspecific example above. even water solutions of soap, may be treatedaccording to the present process if solidified soap bubbles. .Theparticles of such a product are of small average mass, thus promotingclinging of the particles and somewhat impairing the solubilitycharacteristics of the product. This, it will be understood, is anextreme illustration, and is not ordinarily encountered with any soapproducts which occur in the ordinary course of regular manufacture.Particle structures intermediate this extreme and the above describedpreferred product may be obtained from soaps of various water contentsand consistencies. Soap containing a greater percentage of solids thanthat stated in the specific example given above can be handledsatisfactorily, there being no objection to the treatment of soaps ofhigh solid content provided that the soap can be satisfactori y handledand sprayed. Soaps of relatively high solid content lend themselves morereadily to spraying into particles of the proper average mass as abovedescribed, thus facilitating production of a product of desiredcharacteristics and properties in water. It is difficult to produce aproduct of sufficiently great averageparticle mass when very dilutesolutions of soap are employed. 'As a general rule, the present processis adapted to take the soap in substantially the same condition as itoccurs in regular com.- mercial manufacture and to produce therefrom asoap product the particles of wh ch exhibit the characterizingmicroscopic cellular structure as described, either with or without thepresence of primary voids, control of which is described more fullybelow.

The minimum permissible limit of soap temperat'ure is largely, as statedabove, determined'by the ability of the soap to break up into asatisfactory spray, and should be sufficiently high to provide for thisresult. In the specific example given above, the soap temperatures asstated were below atmospheric boiling point; i. e., below the boilingpoint of water at the pressure into which the soap is sprayed. Theliquidity of the soap increases somewhat with increase in temperature,and to promote the uniform distribution .of minute cells throughout theentire body of the individual particles of the finished product arelatively low soap temperature is preferred. At such relatively lowtemperature, the soap material of the individual particles is somewhatmore resistant to the formation of cells of substantial size uponrelease of the gas and to the union of such cells to form primary voids.It will be observed, therefore, that control of soap temperature affordsone means of controlling the average size of the cells within therespective particles and of controlling, within certain limits, thepresence of a principal void or voids. There is no objection toemploying soap temperatures considerably above the atmospheric boilingpoint, and the inventioncont-emplates the use of such relatively highsoap temperatures when desired.

It is, however, desirable that the soap temperature should notsubstantially exceed the boiling point corresponding to the pressure onthe soap prior to spraying for the reason that generation of steam inthe pipe lines leading to the spray is conducive to irregularities inoperation. If soap temperatures substantially above the boiling pointcorresponding to the pressure into which the soap is sprayed areemployed, a certain amount of steam generation and vapor release willtake place within the soap particles by reason of the excess of sensibleheat in the soap which it cannot contain at the reduced pressure. Whilethe amount of steam which can thus be generated and released is notgreat for any practicable temperature to which the soap can be heatedwithout injury prior to spraying, it nevertheless has a cumulativeeffect in the formation of the cellular structure. This effect, coupledwith its liquefying effect on the soap, tends to promote formation oflarger cells within the respective soap particles, particularly at theinner portions of the particles. In carrying out the process, the soaptemperature may be cont-rolled in accordance with the facts juststafedto thereby aid in the production of a product of desiredcharacteristics. Whether the soap temperature be high or low, theproduct obtained from the process will exhibit the ready wetting andsolubility characteristics above described.

The extent of the pressure to which the soap is subjected prior tospraying and particularly the pressure differential which the soapexperiences during spraying are important in determining productcharacteristics. With a high pressure on the soap before spraying and ahigh pressure differential during spraying, correspondingly largequantities of gas can be dissolved in the soap, the air in physicaladmixture with the soap will be compressed into small volume, acorrespondingly Vigorous gas release upon reduction in pressure willoccur, greater inflation of the particle and a. more pronounced cellformation within the particle will result. The minimum desirablepressure is ordinarily that below which the spray will not operatesatisfactorilyor below which insufficient development of the cellstructure within the respective particles results. Higher pressures,with correspondingly-increased amount and rate of gas release, tend toproduce somewhat larger cells before the particle attainsself-sustaining condition, although this condition can be counteractedby -lowering the soap temperature, employing a heavier soap. supplying alarger quantity of solidifying gas to the spray chamber, and in generalby regulating the other conditions of the process to effect rapidconversion of'the sprayed particles to form-retaining c indition,thereby utilizing a greater amount and rate of gas release to effectformation of a greater number of cells within the particle rather thanto produce larger cells. Thus, control of the 5 soap pressure affords ameans of controlling the nature of the cell structure within theparticles of the product, and may be employed to aid in the productionof particles containing larger or smaller cells, as desired. In theabove discussion, the use of a pressure spray has been assumed, but itwill be understood that other types: of atomizing devices can beemployed with good results. With this arrangement the pressure can heapplied by means of the pump which delivers the soup to the sprayingequipment and pressure release can be effected, for example, just aheadof the spray.

Further control of the particle structure can be effected by controllingthe amount of gas which is incorporated with the soap. In general, themore gas that is incorporated the greaterwill be its effect in expandingand forming cells in the product. It will be understood that an excessof gas over that which the soap can completely dissolve may be used. Thepresence of the gas in the soap, particularly the excess which cannot becontained in solution, may be looked upon as a compressible mediumincorporated throughout the soap under pressure which, when releasedfrom such pressure, expands and effects infiation'of the particles andwhich, if properly distributed throughout the soap in finely dividedcondition and held in such finely divided condition by quicksolidification of the soap particles to form-retaining condition, willproduce a cellular structure of the character described within therespective particles. A great excess of gas will tend to produceexcessive inflation and disruption of the soap particles, which resultis ordinarily objectionable. j

The size of the particles produced at the spray is determined largely,in the treatment of any given material, by the character of thespraying'device and the conditions of its operation including theliquidity of the material sprayed. These factors can readily bedetermined and need not here be discussed at length. The size and massofthe particles in the ultimate product are determined principally by theparticle size produced at the spray, the. percentage of solids in thematerial sprayed, and the degree of inflation of the particle. Ingeneral, the larger the particle the greater is the tendency towardlarger or principal interior voids. The particle size and mass are ofparticular importance-to the invention, as fully-discussed above.

The temperature of the'atmosphere in the spray chamber affects particlestructure. Relatively low temperature gas employed in C3c'onjunctionwith the process described herein permits of a cellularstructure of microscopic dimensions extending throughout the body of theparticle; higher temperatures, say upwards of 300 F., ordinarily fosterthe production of voids in the innermost portions of the particles, dueprobably to the expansive efl'ect ofrapidly generated steam within thebody of the particle before the material of the particle has attainedformsnstaining condition. Temperatures below the solidificationtemperature of soap; e. g., ordinary atmospheric air or chilled air, canbe used and are of particular value in producing soap and soap powderproducts wherein a relativelyhigh moisture content is ordinarilydesired.

From the above specification it will be appreciated that the characterof the product, notably its structural characteristics, can becontrolled and varied by appropriate control and variation of processconditions. The relation of the principal process conditions andvariables to the principal product characteristics have been reasonablywell ascertained and have been set forth above at considerable length tofacilitate proper understanding of the invention and to aflford fulltechnical information as to practice of the invention.

The invention is defined in the appended claims. and is defined in termsof the novel process features above described which are J applicablegenerally to the production of a soap product of the general classreferred to herein, and is further defined in its more specific aspectin terms of the characterizing and defining features of the new soapproduct herein disclosed and in terms of. the particular processfeatures which are responsible for such product.

The. expression heavy soap as employed in the appended claims todesignate the character of soap to be processed means a soap stock inthe condition in which it normally occurs in the boiling kettles in theordinary process of commercial manufacture or such soap having added toit appropriate amounts of additional materials such as sodium carbonatesolution, sodium silicate, and generally distributed therein, and havingthe property of readily absorbing water and becoming wet throughout uponcontact with, water, .and ofdissolving readily and rapidly in water,which comprises incorporating a nonaqueous gas into heavy soap which isin a fluent state, effecting a thorough distribution of said gasthroughout the entire body of the soap, the thorough distribution of thegas being effected while the soap is maintained under pressuresubstantially in excess of the atmosphere with its contained gasresultingly compressed, effecting formation of particles of generallyrounded outline having the aforesaid water permeable outer surface andcellular internal structure by spraying said gas-containing soap into aregion of reduced pressure sufliciently low to permit susbtantialexpansion of the contained gas within the respective individual soapparticles, and eifecting a rapid conversion of the said soap particlesinto form-retaining condition thereby to retain said cellular structurewithin the respective individual soap particles and imparting to theproduct the aforesaid properties of ready and rapid wetting anddissolving, said non-aqueous gas being incorporated into the fluent soapin an amount in substantial excess of the quantity of gas which the soapis capable of containing at the reduced pressure of the region intowhich the soap particles are sprayed.

2. The process of producing a soap product composed mainly of particleshaving a generally rounded outline, as distinguished from a sharpangular configuration, having an interior structure substantiallyenclosed by a protective but water permeable outer surface formed withmyriads of minute cells distributed therein, and having the property ofreadily absorbing water and becoming wet throughout upon contact withwater, and of dissolving readily and rapidly in water which comprisesestablishing a flowing stream of heavy soap, incorporating a nonaqueousgas into the soap in a quantity substantially in large excess of thequantity of gas which the soap is capable of containing atatmosphericpressure, efiecting a thorough distribution of gas throughoutthe entire body of soap, the thorough distribution of the gas beingefiected while the soap is maintained under a pressure of upwards of 100lbs. per square inch with its contained gas resultingly compressed,effecting a sub-division of said gas-containing soap into separateindividual particles of generally rounded outline having the aforesaidwater permeable outer surface and cellular internal structure byspraying said gas-containing soap into a region of substantiallyatmospheric pressure to permit substantial expansion of the containedgas within the respective individual soap particles, and effecting arapid conversion of the said soap particles into formretaining conditionthereby to retain said cellular structure within the respectiveindividual soap particles and imparting to the product the aforesaidproperties of ready M and rapid wetting and dissolving;

3. The process of producing a soap product composed mainly of particleshaving a generally rounded out-line, as distinguished from a sharpangular configuration, having an interior structure substantiallyenclosed by a protective but water permeable outer surface formed withmyriads of minute cells distributed therein, and having the property ofreadily absorbing water and becoming wet throughout upon contact withwater, and of dissolving readily and rapidly in water, which comprisesincorporating a non-aqueous gas into heavy soap which. is in a fluentstate, effecting a thorough distribution of said gas throughout theentire body of soap, the thorough distribution of the gas beingefl'ected while the soap is maintained under pressure in excess of 100lbs. per square inch with its contained gas resultingly compressed,efi'ecting formation of particles of generally rounded outline havingthe aforesaid water permeable outer surface and cellular internalstructure by spraying said gascontaining soap into a region of reduce-dpressure sufficiently low to permit substantial expansion of thecontained gas within the respective individual soap particles, andeffecting a rapid conversion of the said soap particles intoform-retaining condition there: by to retain said cellular structurewithin the respective individual soap particles and imparting to theproduct the aforesaid properties of ready and rapid wetting anddissolving, said non-aqueous gas being incorporated into the fluentsoapin an amount in substantial excess of the quantity of gas which the soapis capable of containing at the reduced pressure of the region intowhich the soap particles are sprayed.

4. The process of producing a soap product composed mainly of particleshaving a generally rounded outline, as distinguished from a sharpangular configuration, having an interior structure substantiallyenclosed by a protective but water permeable outer surface formed withmyriads of minute cells distributed therein, and having the property ofreadily absorbing water and becoming wet throughout upon contact withwater, and of dissolving readily and rapidly in water, which comprisesincorporating a non-aque ous gas into heavy soap which is in a fluentstate, effecting a thorough distribution ofv said gas throughout theentire body of soap, the thorough distribution of the gas being effectedwhile the soap is maintained under pressure substantially in excess ofthe atmosphere with its contained gas resultingly compressed, efiectingformation ofparticles of generally rounded outline having the aforesaidwater permeable outer surface and cellular internal structure byspraying said gascontaining soap'into a region of reducedpressuresufliciently low to permit substan-" tial expansion" of the containedgas within.

the respective individual soap particles, the area of the region ofreduced pressure being defined by a treating chamber of an areasuflicient to permit the individual sprayed particles to attainsubstantially form-retaining condition prior to an impingement thereofupon its Walls, and effecting further in-' dependent drying of saidrespective sprayed particles while they contain substantial amount ofgas which has been distributed within the soap thereby to retain saidcellular structure within the respective individual soap particles andimparting to the product the aforesaid properties of. ready and rapidwetting and dissolving, said nonaqueous gas being incorporated into thefluent soap in an amount in substantial excess of the quantity of gaswhich the soap is capable of containing at the produced pressure of theregion into which the soap particles are sprayed. I

5. The process of producing a soap product composed mainly of particleshaving a generally rounded outline, as distinguished rom a sharp angularconfiguration, having an interior structure substantially enclosed byaprotective but water permeable outer surface formed with myria-ds ofminute cells distributed therein, and having the property of readilyabsorbing water and becoming wet throughout upon contact with water, andof dissolving readily and rapidly in water, which comprisesincorporating nonaqueous gas into heavy soap which is in a fluent state,elfecting a thorough distribution of said gas throughout the entire Ibody of the soap, the thorough distribution of the gas being effectedwhile the soap is maintained under pressure in excess of 100 lbs. persquare inch with its contained gas resultingly compressed, effectingformation of articles of generally rounded outline havlng the aforesaidwater permeable outer surface of cellular internal structure by sprayingsaid gas-containing soap coinci dent with the reduction of pressurethereon to permit substantial expansion of the contained gas within therespective individual soap particles, and effecting a rapid conversionof the said soap particles into formretaining condition thereby toretain said cellular structure within the respective ,individual soapparticles and impartin to the product the aforesaid properties 0% readyand rapid wetting and dissolving,'said nonaqueous gas being incorporatedinto the fluent soap in an amount in substantial ex cess of the quantityof gas which the soap iscapable of containing at the reduced pressure towhich it is subjected coincident with the spraying thereof.

6. The process of producing a soap product composed mainly of particleshaving a enerally rounded outline, as distinguished rom a sharp angularconfiguration, having an interior structure substantially enclosed by aprotective but water permeablevouter surface formed with myriads ofminute cells distributed therein, and having the property of readilyabsorbing water and becom-. ing wet throughout upon contact with water,and of dissolving readily and rapidl 'in water, which comprisesestablishing a owing stream of soap having solid content of of at leastabout 60%, incorporating a nonaqueous gas -into said soap, effecting athorough distribution of said gas throughout the entire body of soap,the thorough distribution of the gas being efiected while the soap ismaintained under pressure substantially in excess of the atmosphere withits contained gas resultingly compressed, effecting formationof'particles of generally rounded outline having the aforesaid waterpermeable outer surface and cellular internal structure by spraying saidgas-containing soap into a region of reduced pressure sufliciently lowto permit expansion of the contained gas within the respectiveindividual soap particles, and effecting a-rapid con; version of thesaid soap particles into formretaining condition, thereby to retain saidcellular structure within the respectiveindividual soap particles andimpartin to the product the aforesaid properties 0 ready and rapidwetting and dissolving said nonaqueous gas being incorporated into thefluent soap in an amount in substantial excess of the uantity of gaswhich the soap iscapableo the region into w sprayed.

7. The process of producing a soap product composed mainly of partlcleshaving a generally rounded outline, as distinguished from a sharpangular configuration, havin an interior structure substantially encloseby a protective but water permeable outer surface formed with myriads ofminute cells distributed therein, and having the property of readilyabsorbing water and becomin wet throughout upon contact with water, anof dissolving readily and rapidly in water, which comprises establishina flowing containin at the reduced pressure 0 ich the soap particles arestream of soap having a solid content of at least about 60%,incorporating a nonaqueous gas into said soap, agitating the soap in theflowing stream in the presence of the gas for elfecting a thoroughdistribution of mosphere with its contained gas resultingly compressed,effecting formation of particles of generally rounded outline having theaforesaid water permeable outer surface and cellular internal structureby spraying said gas-containing soap into a region of reduced pressuresufficiently low to permit expansion of the contained gas within therespective individual soap particles, and effecting a rapid conversionof the said soap particles into form-retaining condition by bringing a 5current of relatively low temperature air into contact with saidparticles, the temperature of said air being sufliciently low so thatthe maximum temperature attained by the sprayed particles beforesolidification thereof does not exceed the atmospheric boiling oint ofwater, thereby to retain said celluar structure within the respectiveindividual soap articles and imparting to the product the a oresaidproperties of ready and rapid l5 wetting and dissolving, saidnon-aqueous gas being incorporated into the fluent soap in an amount insubstantial excess of the quantity of gas which the soap is capable ofcontaining at the reduced pressure of the region into which the soapparticles are sprayed. 8. The process of producing a soap productcomposed mainly of particles having a generally rounded outline, asdistinguished rom a sharp angular configuration, having an interiorstructure substantially enclosed by a protective but water permeableouter surface formed with myriads of minute cells distributed therein,and having the property of readily absorbing water and becomin wetthroughout upon contact with water, an

of dissolving readily and rapidly in water which comprises establishinga flowing stream of heavy soap, incorporating a nonaqueous gas into thesoap, effecting a thorough distribution of said gas throu hout theentire body of soap, the thorough distribution of the gas beingefl'ected while the soap is maintained under pressure in excess of 100lbs. per square inch for a period of at 40 least three minutes,effecting formation of particles of generally rounded outline having theaforesaid water permeable outer surface and cellular internal structureby spraymg said gas-containing soap into a region of reduced pressuresufficiently low to permit substantial expansion of the contained gaswithin the respective individual soap particles, and effecting a rapidconversion of the said. soap particles into form-retaining conditionthereby to retain said cellular structure within the respectiveindividual soap particles and imparting to the product the aforesaidproperties of ready and rapid wetting and dissolving, said non-aqueousgas being incorporated into the fluent soap in an amount in substantialexcess of the quantity of gas which the soap is capable of containing atthe reduced pressure of the region into which the soap articles aresprayed.

In testimony w ereof I aflix my signature.

DALLAS R. LAMONT.

